Abstract
The jelly from achenes of Ficus pumila var. awkeotsang (FPAA) is a famous beverage ingredient in Taiwan. In this work, ficumarin (1), a new compound was obtained from its twigs (FPAT) and elucidated with comprehensive spectroscopic data. The biosynthetic origin was proposed from the p-coumaroyl-CoA pathway. Alloxanthoxyletin, betulinic acid, and catechin were identified as the major and active constituents responsible for relieving neutrophilic inflammation by FPAT. Among them, the most potent alloxanthoxyletin was found to interact with PRO350 and GLU377 of human INOSOX. Further, Nrf2 activating capacity of the FPAT fraction and its coumarins was confirmed. With the analysis of LC-MS/MS data and feature-based molecular networking, coumarins were found as the dominant and responsible components. Notably, alloxanthoxyletin increased Nrf2 expression by up to 816.8 ± 58% due to the interacting with the VAL561, THR560 and VAL420 residues of 5FNQ protein. COVID-19 Docking Server simulation indicated that pyranocoumarins would promisingly interfere with the life cycle of SARS-CoV-2. FPAT was proven to exert anti-inflammatory activity on neutrophils and to activate Nrf2, and may likely be developed as a complementary supplement in the treatment of COVID-19 patients.